The connection between K64F output and 74LS07 input is OK?

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The connection between K64F output and 74LS07 input is OK?

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masakazunotsu
Contributor I

Kinetis K64F output pins are connecting to input pins of SN74LS07 buffer.

The Vcc of SN74LS07 is 5V. 

It works normally.

However, I am worried about the reverse current to K64F Vdd (3.3V) from SN74LS07 input pin.
SN74LS07 datasheet says "I_IH is 20uA, I_IL is -0.2mA".

Are these value no problem for K64F ?


I had thought that All digital I/O pins are 5V tolerant.
But some people say that "The Kinetis Port pins are only 5V tolerant as inputs. The outputs are not 5V tolerant." in other threads.
Which is true?

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IvanRuiz
NXP Employee
NXP Employee

Dear Masakazu Notsu,

All 5V dital I/O are clamped to VSS through a protection diode.

Please refer to K64's datasheet, chapter 2.2.1 Voltage and current operating requirements for more information:

http://cache.freescale.com/files/microcontrollers/doc/data_sheet/K64P144M120SF5.pdf 

Regards,

Ivan.

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